Coronaviruses infect and cause disease in a wide variety of species, including bats, birds, cats, dogs, pigs, mice, horses, whales, and humans. Bats act as a natural reservoir for coronaviruses. Most infections caused by human coronaviruses are relatively mild. However, the outbreak of severe acute respiratory syndrome (SARS) caused by SARC-CoV in 2002-2003, and fatal infection in 2012 caused by a recently identified coronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV, also known as hCoV-EMC or NCoV) demonstrated that coronaviruses are also able to cause severe, sometimes fatal disease in humans.
The recently identified coronavirus MERS-CoV has over 40% mortality rate among the infected individuals. This virus also demonstrates person-to-person transmission, posing a continuous threat to public health worldwide. Thus, development of vaccines and antiviral agents against this new virus are urgently needed.